https://bugzilla.kernel.org/show_bug.cgi?id=213353
Bug ID: 213353 Summary: IRQs for onboard UARTs are not level-triggered with IRQNoFlags even if the parent section has the defaults in PRS Product: ACPI Version: 2.5 Kernel Version: 5.12.8 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: enhancement Priority: P1 Component: Config-Interrupts Assignee: acpi_config-interru...@kernel-bugs.osdl.org Reporter: zbos...@pr.hu Regression: No I have tablet with that supposedly has a serial-attached EETI touchscreen device. # dmesg | grep ttyS0 [ 3.896102] 00:01: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A When trying to use it via inputattach, it fails: # inputattach -eeti /dev/ttyS0 inputattach: device initialization failed The IRQ set up for the UART is edge-triggered, while it's attached to the LPC bus and should be level-trigered: # grep " 4:" /proc/interrupts 4: 0 1 0 0 IO-APIC 4-edge Disassembling the DSDT, I can see this: Scope (_SB) { ... /* IRQ defaults for (E)ISA/LPC IRQs? */ Name (PRSA, ResourceTemplate () { IRQ (Level, ActiveLow, Shared, ) {3,4,5,6,10,11,12,14,15} }) Alias (PRSA, PRSB) Alias (PRSA, PRSC) Alias (PRSA, PRSD) Alias (PRSA, PRSE) Alias (PRSA, PRSF) Alias (PRSA, PRSG) Alias (PRSA, PRSH) The serial device is in the above parent scope: Device (IURT) { Name (_HID, EisaId ("PNP0501") /* 16550A-compatible COM Serial Port */) // _HID: Hardware ID Name (_UID, One) // _UID: Unique ID Method (_STA, 0, Serialized) // _STA: Status { If ((USEL == Zero)) { UI4E = One C1EN = One Return (0x0F) } Return (Zero) } Method (_DIS, 0, Serialized) // _DIS: Disable Device { If (((BDID != One) && ((BDID != 0x0A) && (BDID != 0x09)))) { UI4E = Zero C1EN = Zero } } Method (_CRS, 0, Serialized) // _CRS: Current Resource Settings { Name (BUF0, ResourceTemplate () { IO (Decode16, 0x03F8, // Range Minimum 0x03F8, // Range Maximum 0x01, // Alignment 0x08, // Length ) IRQNoFlags () {4} }) Return (BUF0) /* \_SB_.PCI0.LPCB.IURT._CRS.BUF0 */ } } It seems to me that the IRQ default parameters from PRS are not applied to the PNP0501 device and as such, the serial device doesn't work. -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug. _______________________________________________ acpi-bugzilla mailing list acpi-bugzilla@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla